Normally the Moon orbits much slower than the earth rotates so it rises in the east and sets in the west, however at 420km it orbits much faster, faster than the earth rotates underneath, therefore it will rise in the west and set in the east.

...The Moon would orbit very fast, somewhere between 130 mins and 90 mins. ...The time in the video is sped up. The moon would transverse the sky slower. Like 10 mins (rough guess)

Okay so apparently the moon COULD orbit the earth so close if it were going fast enough, but being so close would strip the atmosphere from earth, cause the ocean tides to destroy all land life, and all around make earth a shitty place to live. But that's all just speculation, I say we tractor beam that f***er and see what really happens.

Hit the jump for a video of a moon so close you feel like you could reach out and touch it.

Thanks to Ramblow, who wishes earth orbited the sun as close as the moon does earth.

That's not even close to what it would look like, because this distance is well within Roche limit, meaning that the Moon would disintegrate into a planetary ring due to tidal forces. It would be an awesome looking ring, though.

Darkunit

Roche limit doesn't apply here, as the Moon is held together by more than just its own gravity. Roche limit is more about clusters of gravity bound rock, liquids, or dust.

Konstantin

First of all, any sufficiently large body behaves as a liquid. The material strengths are not comparable to gravitational forces. Hence the round shape of the body. But even for objects with significant tensile strength, such as monolith asteroids, the Roche limit can be defined. Large enough asteroid would be torn apart at an approach this near. With something as large as the Moon, there is just no question about it. It would be shredded and debris would form a ring.

Darkunit

Nope. A "sufficiently" large body doesn't behave as a liquid, or large mass planets wouldn't stay together spinning around their own home stars. Nor would gas giants hold together as they do in systems with massive stars. Its dependent on the body in question. The moon is made of mainly iron and would easily hold together. Stop googling this stuff to sound smart. Hell, even where I think you are looking disproves your point...

~via wikipedia~Jupiter's moon Metis and Saturn's moon Pan are examples of such satellites, which hold together because of their tensile strength (that is, they are solid and not easily pulled apart)

The moon is solid and would not rip apart. Pan and Metis are well within the RL of Jupiter and Saturn.

Also, don't use "first of all" if you aren't going to enumerate any other points. I was looking for your second enumerated point and left disappointed.

Konstantin

"A planetary-mass object (PMO), planemo, or planetary body is a celestial object with a mass that falls within the range of the definition of a planet: massive enough to achieve hydrostatic equilibrium (to be rounded under its own gravity)." Moon is a PMO. It's own gravity overcomes its own tensile strength. The surface of the Moon is a surface of constant potential to within a few km.

The examples you've given are both rocks merely a few km across. If these things weren't orbiting their corresponding planets, we'd call these asteroids.

The Moon is over 3,000 km across. It is in hydrostatic equilibrium. The gravitational forces such an object experiences are significantly greater than tensile strength. Forget rocks. If Moon was made of solid steel, the tidal forces this close to Earth would overcome the tensile strength and the Moon would flow as if liquid. It would be stretched and subsequently ripped into fragments until it forms a nice ring around the planet.

Now, I'm too lazy to run the numbers on the spherical object. Lets take a solid steel wire 3,000 km long and place it with one end just 400km over Earth's surface. Lets make it have cross-section area of 1m². 7g/cm³ is on the light side for steel, and 10GPa is a bit of an over-estimate for its tensile strength, just to give it a best chance of working. Assuming uniform rotation, again to minimize tension, the net acceleration is an integral over ω²r - GM/r². Setting that to zero we get center of gravity 1,408 km from the lower end of the cable. Integrating effective weight up to this point, we get the tension in the cable at 32GPa. Snap!

This is for a perfect, defect-free wire of impossibly light and impossibly strong alloy, which I've even taken to be shorter than Moon's diameter. The Moon doesn't stand a chance.

Foresight

Careful...the moon's mass would be significantly greater than what it is now if it was made completely out of a much more dense material. Let me ask you this though...if two Earths were placed within close proximity of each other, would they both break apart?

Kenlin Bros

Dirty space news!

JJtoob

I just think you should be able to see the shadow of the moon coming at you and moving away, and would you not see some glow around the moon? Sure it's completely covering where it's recorded from, but it doesn't cover the whole light side of Earth, you should see a bright horizon as well.

Iknowyou

There should be more water, a lot more water. If the moon were that close, it would probably be dragging the oceans across the continents.

JJtoob

At the very least some major storms as the moon passes, especially at that speed.

ODwanKenObi

That's no moon!! Oh yes...yes it is...

Jeremy Tilton

Awesome, it's especially cool that we'd have a short "night" (full lunar eclipse) in between nights and the moon's phases would change throughout the day based on position in sky and time. That said, I'm with Amsel, not sure why the dude had any transparency on the "moon" layer in whatever he was using to make the video.

Trevor Troake

im no astronomer, but i dont think its transparency. its our atmosphere, in the shots before the moon covers the sun, we see the clouds and and the blue of the sky. thats all our atmosphere. once the moon blocks the sun it appears to become "solid" because without the suns light reflecting off our atmosphere its much easier to see through it. hope this helps :)

Jeremy Tilton

Right, as is the case as the moon appears now. I guess I expected the lit parts of the moon to be brighter.

Hpsf Tofu

That's correct, there's no Transparency at all, It's simply whereever there is no Light on the moon, appears black, and since space is black. black on black looks invisable, The atmosphere acts as an Additive filter, adding blue to whatever is behind it, ie,, space or lit pieces of the moon